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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.lang3.text;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    import java.util.Map;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    /**<a name="line.21"></a>
<FONT color="green">022</FONT>     * Lookup a String key to a String value.<a name="line.22"></a>
<FONT color="green">023</FONT>     * &lt;p&gt;<a name="line.23"></a>
<FONT color="green">024</FONT>     * This class represents the simplest form of a string to string map.<a name="line.24"></a>
<FONT color="green">025</FONT>     * It has a benefit over a map in that it can create the result on<a name="line.25"></a>
<FONT color="green">026</FONT>     * demand based on the key.<a name="line.26"></a>
<FONT color="green">027</FONT>     * &lt;p&gt;<a name="line.27"></a>
<FONT color="green">028</FONT>     * This class comes complete with various factory methods.<a name="line.28"></a>
<FONT color="green">029</FONT>     * If these do not suffice, you can subclass and implement your own matcher.<a name="line.29"></a>
<FONT color="green">030</FONT>     * &lt;p&gt;<a name="line.30"></a>
<FONT color="green">031</FONT>     * For example, it would be possible to implement a lookup that used the<a name="line.31"></a>
<FONT color="green">032</FONT>     * key as a primary key, and looked up the value on demand from the database<a name="line.32"></a>
<FONT color="green">033</FONT>     *<a name="line.33"></a>
<FONT color="green">034</FONT>     * @since 2.2<a name="line.34"></a>
<FONT color="green">035</FONT>     * @version $Id: StrLookup.java 1153484 2011-08-03 13:39:42Z ggregory $<a name="line.35"></a>
<FONT color="green">036</FONT>     */<a name="line.36"></a>
<FONT color="green">037</FONT>    public abstract class StrLookup&lt;V&gt; {<a name="line.37"></a>
<FONT color="green">038</FONT>    <a name="line.38"></a>
<FONT color="green">039</FONT>        /**<a name="line.39"></a>
<FONT color="green">040</FONT>         * Lookup that always returns null.<a name="line.40"></a>
<FONT color="green">041</FONT>         */<a name="line.41"></a>
<FONT color="green">042</FONT>        private static final StrLookup&lt;String&gt; NONE_LOOKUP;<a name="line.42"></a>
<FONT color="green">043</FONT>        /**<a name="line.43"></a>
<FONT color="green">044</FONT>         * Lookup that uses System properties.<a name="line.44"></a>
<FONT color="green">045</FONT>         */<a name="line.45"></a>
<FONT color="green">046</FONT>        private static final StrLookup&lt;String&gt; SYSTEM_PROPERTIES_LOOKUP;<a name="line.46"></a>
<FONT color="green">047</FONT>        static {<a name="line.47"></a>
<FONT color="green">048</FONT>            NONE_LOOKUP = new MapStrLookup&lt;String&gt;(null);<a name="line.48"></a>
<FONT color="green">049</FONT>            StrLookup&lt;String&gt; lookup = null;<a name="line.49"></a>
<FONT color="green">050</FONT>            try {<a name="line.50"></a>
<FONT color="green">051</FONT>                final Map&lt;?, ?&gt; propMap = System.getProperties();<a name="line.51"></a>
<FONT color="green">052</FONT>                @SuppressWarnings("unchecked") // System property keys and values are always Strings<a name="line.52"></a>
<FONT color="green">053</FONT>                final Map&lt;String, String&gt; properties = (Map&lt;String, String&gt;) propMap;<a name="line.53"></a>
<FONT color="green">054</FONT>                lookup = new MapStrLookup&lt;String&gt;(properties);<a name="line.54"></a>
<FONT color="green">055</FONT>            } catch (SecurityException ex) {<a name="line.55"></a>
<FONT color="green">056</FONT>                lookup = NONE_LOOKUP;<a name="line.56"></a>
<FONT color="green">057</FONT>            }<a name="line.57"></a>
<FONT color="green">058</FONT>            SYSTEM_PROPERTIES_LOOKUP = lookup;<a name="line.58"></a>
<FONT color="green">059</FONT>        }<a name="line.59"></a>
<FONT color="green">060</FONT>    <a name="line.60"></a>
<FONT color="green">061</FONT>        //-----------------------------------------------------------------------<a name="line.61"></a>
<FONT color="green">062</FONT>        /**<a name="line.62"></a>
<FONT color="green">063</FONT>         * Returns a lookup which always returns null.<a name="line.63"></a>
<FONT color="green">064</FONT>         *<a name="line.64"></a>
<FONT color="green">065</FONT>         * @return a lookup that always returns null, not null<a name="line.65"></a>
<FONT color="green">066</FONT>         */<a name="line.66"></a>
<FONT color="green">067</FONT>        public static StrLookup&lt;?&gt; noneLookup() {<a name="line.67"></a>
<FONT color="green">068</FONT>            return NONE_LOOKUP;<a name="line.68"></a>
<FONT color="green">069</FONT>        }<a name="line.69"></a>
<FONT color="green">070</FONT>    <a name="line.70"></a>
<FONT color="green">071</FONT>        /**<a name="line.71"></a>
<FONT color="green">072</FONT>         * Returns a lookup which uses {@link System#getProperties() System properties}<a name="line.72"></a>
<FONT color="green">073</FONT>         * to lookup the key to value.<a name="line.73"></a>
<FONT color="green">074</FONT>         * &lt;p&gt;<a name="line.74"></a>
<FONT color="green">075</FONT>         * If a security manager blocked access to system properties, then null will<a name="line.75"></a>
<FONT color="green">076</FONT>         * be returned from every lookup.<a name="line.76"></a>
<FONT color="green">077</FONT>         * &lt;p&gt;<a name="line.77"></a>
<FONT color="green">078</FONT>         * If a null key is used, this lookup will throw a NullPointerException.<a name="line.78"></a>
<FONT color="green">079</FONT>         *<a name="line.79"></a>
<FONT color="green">080</FONT>         * @return a lookup using system properties, not null<a name="line.80"></a>
<FONT color="green">081</FONT>         */<a name="line.81"></a>
<FONT color="green">082</FONT>        public static StrLookup&lt;String&gt; systemPropertiesLookup() {<a name="line.82"></a>
<FONT color="green">083</FONT>            return SYSTEM_PROPERTIES_LOOKUP;<a name="line.83"></a>
<FONT color="green">084</FONT>        }<a name="line.84"></a>
<FONT color="green">085</FONT>    <a name="line.85"></a>
<FONT color="green">086</FONT>        /**<a name="line.86"></a>
<FONT color="green">087</FONT>         * Returns a lookup which looks up values using a map.<a name="line.87"></a>
<FONT color="green">088</FONT>         * &lt;p&gt;<a name="line.88"></a>
<FONT color="green">089</FONT>         * If the map is null, then null will be returned from every lookup.<a name="line.89"></a>
<FONT color="green">090</FONT>         * The map result object is converted to a string using toString().<a name="line.90"></a>
<FONT color="green">091</FONT>         *<a name="line.91"></a>
<FONT color="green">092</FONT>         * @param &lt;V&gt; the type of the values supported by the lookup<a name="line.92"></a>
<FONT color="green">093</FONT>         * @param map  the map of keys to values, may be null<a name="line.93"></a>
<FONT color="green">094</FONT>         * @return a lookup using the map, not null<a name="line.94"></a>
<FONT color="green">095</FONT>         */<a name="line.95"></a>
<FONT color="green">096</FONT>        public static &lt;V&gt; StrLookup&lt;V&gt; mapLookup(Map&lt;String, V&gt; map) {<a name="line.96"></a>
<FONT color="green">097</FONT>            return new MapStrLookup&lt;V&gt;(map);<a name="line.97"></a>
<FONT color="green">098</FONT>        }<a name="line.98"></a>
<FONT color="green">099</FONT>    <a name="line.99"></a>
<FONT color="green">100</FONT>        //-----------------------------------------------------------------------<a name="line.100"></a>
<FONT color="green">101</FONT>        /**<a name="line.101"></a>
<FONT color="green">102</FONT>         * Constructor.<a name="line.102"></a>
<FONT color="green">103</FONT>         */<a name="line.103"></a>
<FONT color="green">104</FONT>        protected StrLookup() {<a name="line.104"></a>
<FONT color="green">105</FONT>            super();<a name="line.105"></a>
<FONT color="green">106</FONT>        }<a name="line.106"></a>
<FONT color="green">107</FONT>    <a name="line.107"></a>
<FONT color="green">108</FONT>        /**<a name="line.108"></a>
<FONT color="green">109</FONT>         * Looks up a String key to a String value.<a name="line.109"></a>
<FONT color="green">110</FONT>         * &lt;p&gt;<a name="line.110"></a>
<FONT color="green">111</FONT>         * The internal implementation may use any mechanism to return the value.<a name="line.111"></a>
<FONT color="green">112</FONT>         * The simplest implementation is to use a Map. However, virtually any<a name="line.112"></a>
<FONT color="green">113</FONT>         * implementation is possible.<a name="line.113"></a>
<FONT color="green">114</FONT>         * &lt;p&gt;<a name="line.114"></a>
<FONT color="green">115</FONT>         * For example, it would be possible to implement a lookup that used the<a name="line.115"></a>
<FONT color="green">116</FONT>         * key as a primary key, and looked up the value on demand from the database<a name="line.116"></a>
<FONT color="green">117</FONT>         * Or, a numeric based implementation could be created that treats the key<a name="line.117"></a>
<FONT color="green">118</FONT>         * as an integer, increments the value and return the result as a string -<a name="line.118"></a>
<FONT color="green">119</FONT>         * converting 1 to 2, 15 to 16 etc.<a name="line.119"></a>
<FONT color="green">120</FONT>         * &lt;p&gt;<a name="line.120"></a>
<FONT color="green">121</FONT>         * The {@link #lookup(String)} method always returns a String, regardless of<a name="line.121"></a>
<FONT color="green">122</FONT>         * the underlying data, by converting it as necessary. For example:<a name="line.122"></a>
<FONT color="green">123</FONT>         * &lt;pre&gt;<a name="line.123"></a>
<FONT color="green">124</FONT>         * Map&lt;String, Object&gt; map = new HashMap&lt;String, Object&gt;();<a name="line.124"></a>
<FONT color="green">125</FONT>         * map.put("number", Integer.valueOf(2));<a name="line.125"></a>
<FONT color="green">126</FONT>         * assertEquals("2", StrLookup.mapLookup(map).lookup("number"));<a name="line.126"></a>
<FONT color="green">127</FONT>         * &lt;/pre&gt;<a name="line.127"></a>
<FONT color="green">128</FONT>         * @param key  the key to be looked up, may be null<a name="line.128"></a>
<FONT color="green">129</FONT>         * @return the matching value, null if no match<a name="line.129"></a>
<FONT color="green">130</FONT>         */<a name="line.130"></a>
<FONT color="green">131</FONT>        public abstract String lookup(String key);<a name="line.131"></a>
<FONT color="green">132</FONT>    <a name="line.132"></a>
<FONT color="green">133</FONT>        //-----------------------------------------------------------------------<a name="line.133"></a>
<FONT color="green">134</FONT>        /**<a name="line.134"></a>
<FONT color="green">135</FONT>         * Lookup implementation that uses a Map.<a name="line.135"></a>
<FONT color="green">136</FONT>         */<a name="line.136"></a>
<FONT color="green">137</FONT>        static class MapStrLookup&lt;V&gt; extends StrLookup&lt;V&gt; {<a name="line.137"></a>
<FONT color="green">138</FONT>    <a name="line.138"></a>
<FONT color="green">139</FONT>            /** Map keys are variable names and value. */<a name="line.139"></a>
<FONT color="green">140</FONT>            private final Map&lt;String, V&gt; map;<a name="line.140"></a>
<FONT color="green">141</FONT>    <a name="line.141"></a>
<FONT color="green">142</FONT>            /**<a name="line.142"></a>
<FONT color="green">143</FONT>             * Creates a new instance backed by a Map.<a name="line.143"></a>
<FONT color="green">144</FONT>             *<a name="line.144"></a>
<FONT color="green">145</FONT>             * @param map  the map of keys to values, may be null<a name="line.145"></a>
<FONT color="green">146</FONT>             */<a name="line.146"></a>
<FONT color="green">147</FONT>            MapStrLookup(Map&lt;String, V&gt; map) {<a name="line.147"></a>
<FONT color="green">148</FONT>                this.map = map;<a name="line.148"></a>
<FONT color="green">149</FONT>            }<a name="line.149"></a>
<FONT color="green">150</FONT>    <a name="line.150"></a>
<FONT color="green">151</FONT>            /**<a name="line.151"></a>
<FONT color="green">152</FONT>             * Looks up a String key to a String value using the map.<a name="line.152"></a>
<FONT color="green">153</FONT>             * &lt;p&gt;<a name="line.153"></a>
<FONT color="green">154</FONT>             * If the map is null, then null is returned.<a name="line.154"></a>
<FONT color="green">155</FONT>             * The map result object is converted to a string using toString().<a name="line.155"></a>
<FONT color="green">156</FONT>             *<a name="line.156"></a>
<FONT color="green">157</FONT>             * @param key  the key to be looked up, may be null<a name="line.157"></a>
<FONT color="green">158</FONT>             * @return the matching value, null if no match<a name="line.158"></a>
<FONT color="green">159</FONT>             */<a name="line.159"></a>
<FONT color="green">160</FONT>            @Override<a name="line.160"></a>
<FONT color="green">161</FONT>            public String lookup(String key) {<a name="line.161"></a>
<FONT color="green">162</FONT>                if (map == null) {<a name="line.162"></a>
<FONT color="green">163</FONT>                    return null;<a name="line.163"></a>
<FONT color="green">164</FONT>                }<a name="line.164"></a>
<FONT color="green">165</FONT>                Object obj = map.get(key);<a name="line.165"></a>
<FONT color="green">166</FONT>                if (obj == null) {<a name="line.166"></a>
<FONT color="green">167</FONT>                    return null;<a name="line.167"></a>
<FONT color="green">168</FONT>                }<a name="line.168"></a>
<FONT color="green">169</FONT>                return obj.toString();<a name="line.169"></a>
<FONT color="green">170</FONT>            }<a name="line.170"></a>
<FONT color="green">171</FONT>        }<a name="line.171"></a>
<FONT color="green">172</FONT>    }<a name="line.172"></a>




























































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